Acidic Peptizing Agent Effect on Anatase-Rutile Ratio and Photocatalytic Performance of TiO2 Nanoparticles

TiO(2) nanoparticles were synthesized from titanium isopropoxide by a simple peptization method using sulfuric, nitric, and acetic acids. The effect of peptizing acid on physicochemical and photocatalytic properties of TiO(2) powders was studied. The structural properties of synthesized TiO(2) powders were analyzed by using XRD, TEM, N(2)-physisorption, Raman, DR UV-vis, FTIR, and X-ray photoelectron spectroscopy techniques. The characterization results showed that acetic acid peptization facilitated the formation of pure anatase phase after thermal treatment at 500 °C; in contrast, nitric acid peptization led to a major rutile phase formation (67%). Interestingly, the sample peptized using sulfuric acid yielded 95% anatase and 5% rutile phases. The photocatalytic activity of synthesized TiO(2) nanoparticles was evaluated for degradation of selected organic dyes (crystal violet, methylene blue, and p-nitrophenol) in aqueous solution. The results confirmed that the TiO(2) sample peptized using nitric acid (with rutile and anatase phases in 3:1 ratio) offered the highest activity for degradation of organic dyes, although, TiO(2) samples peptized using sulfuric acid and acetic acid possessed smaller particle size, higher band gap energy, and high surface area. Interestingly, TiO(2) sample peptized with nitric acid possessed relatively high theoretical photocurrent density (0.545 mAcm(−2)) and pore diameter (150 Å), which are responsible for high electron-hole separation efficiency and diffusion and mass transportation of organic reactants during the photochemical degradation process. The superior activity of TiO(2) sample peptized with nitric acid is due to the effective transfer of photogenerated electrons between rutile and anatase phases. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s11671-018-2465-x) contains supplementary material, which is available to authorized users.